The project describes a one-year prospective study of 125 non-depressed patients newly admitted to a long-term care facility that includes, under one roof, a chronic care hospital and a skilled nursing facility. The focus of the project is to study factors associated with the onset and course of depression occurring after admission. For those patients who become significantly depressed, and antidepressant drug protocol is included to study more precisely their dosage requirements (acute and maintenance phase) and a variety of biologic factors that may influence therapeutic response (antecedent factors and concurrent factors). A number of variables may bear on the onset, course and antidepressant drug responsiveness of depressive illness. Many of these variables would permit interventions if they are found to relate to the onset of depression. Such variables include: (1) baseline demographic factors; (2) baseline and follow-up psychologic variables; (3) baseline and follow-up physical health status; (4) baseline and follow-up biologic parameters (eg: platelet receptors; platelet MAO; quantitative EEG); (4) institutional factors: a) ward morale, ambiance, policies, etc; b) within institutional events (eg: relocations; family visits; medical stability over time). The objectives of the study are to define the relevance of these factors to depression; to develop "risk profiles" for subsequent patients as to the development of depression; and to enhance our knowledge of antidepressant drug usage in this population.